Blackout throughout San Diego County

Power outages began to affect several parts of the local region at about 3:40 p.m., including The San Diego Union-Tribune offices in Mission Valley. Here's how it unraveled, according to the social networks.

Power outages have been reported across San Diego County, from San Marcos to San Carlos, including much of the city of San Diego. A San Diego Gas & Electric Co. spokesman said utility officials were trying to determine the source and extent of the outage.